Radiographic Evidence of Dental Complications after Mandibular Distraction Osteogenesis: Inverted-L versus Oblique Osteotomy.

Background: Patients with micrognathia undergoing mandibular distraction osteogenesis (MDO) for functional and aesthetic improvement are at significant risk for dental complications. The authors investigated the association of 2 osteotomy patterns-oblique and inverted-L-with risk to developing dentition.

Methods: A senior orthodontist (H.D.N.) performed a retrospective review of dental radiographs of patients undergoing MDO with confirmed oblique or inverted-L osteotomies between 2012 and 2022. Images were assessed for evidence of missing, damaged, or displaced teeth, and proportion of affected hemimandibles by injury type and median number of affected teeth per hemimandible were compared between groups using appropriate statistical methodology.

Results: Analysis included 44 patients (23 oblique, 21 inverted-L) and 85 hemimandibles (45 oblique, 40 inverted-L). Mean age at surgery was 3.1 ± 4.6 years, and mean time to imaging was 4.9 ± 4.1 years; there was no difference between groups ( P = 0.23, P = 0.34, respectively). Oblique osteotomy was associated with greater odds of missing teeth (odds ratio [OR], 13.3, P < 0.001), damaged teeth (OR, 3.2; P = 0.02), and any dental injury (OR, 39.9; P < 0.001) compared with inverted-L, as well as greater number of missing teeth (β = 0.6; P < 0.01), damaged teeth (β = 0.3; P = 0.02), and total number of affected teeth (β = 0.9; P < 0.001). There was no difference in incidence ( P = 0.5) or number ( P = 0.4) of displaced teeth between groups.

Conclusions: Inverted-L osteotomies were associated with fewer dental complications compared with oblique osteotomy at all ages studied. Although longer-term follow-up and prospective data are needed before definitive recommendations can be made, these data are helpful to surgeons as they plan MDO.

Clinical question/level of evidence: Therapeutic, III.